1. Field of the Invention
The present invention relates to a data processing apparatus, and more particularly to a process for deleting moving image data from a recording medium.
2. Description of the Related Art
Recently, a number of apparatuses for recording an AV (audiovisual) signal, such as a video signal, or the like, on a disk-type information recording medium has been proposed.
In apparatuses of this type, as described in Japanese Patent Application Laid-Open (Kokai) No. 2002-157859 (corresponding US application No.: AA2002150383), information relating to management of data recorded on a recording medium is recorded in the form of a file. The data recorded on the recording medium and reproduced information are appropriately managed.
An application format for appropriately managing the data and the reproduced information on an information recording medium will now be described. This format has two layers, i.e., PlayList and Clip, for managing AV streams. FIG. 1 is a diagram illustrating the relationship between Clips and PlayLists. Volume Information manages all Clips and PlayLists on a disk. An AV stream and its attribute information are considered as one object, or “Clip.” An AV stream file is called a “Clip AV stream file,” and attribute information thereof is called a “Clip Information file.”
A Clip AV stream file stores data in which an MPEG2 transport stream is arranged in a structure provided by a DVR (digital video recording) application format. In general, a data file used in a computer, or the like is dealt with as a byte string. The contents of a Clip AV stream file are developed on the time base, and PlayList assigns an access point in a Clip mainly with a time stamp. When the time stamp of an access point in a Clip is given, a Clip Information file is useful for finding information relating to an address (a data-byte position) where decoding of a stream is to be started in the Clip AV stream file. PlayList is introduced for allowing selection of a reproduction section desired by the user to see in a Clip, and for easy editing of the reproduction section.
A PlayList is a set of reproduction sections in a Clip. A reproduction section in a Clip is called a “PlayItem,” which is represented by a pair of IN point and OUT point. Accordingly, a PlayList is a set of PlayItems. PlayList has two types, i.e., Real PlayList and Virtual PlayList.
A Real PlayList is considered to share a stream portion of a Clip referred to by the Real PlayList. That is, a Real PlayList occupies a data capacity corresponding to a stream portion of the referred Clip in a disk. A PlayItem of a Real PlayList does not assign an overlapped reproduction section of one Clip AV stream. When an AV stream is recorded as a new Clip, a Real PlayList that refers to a reproducible range of entirety of the Clip is automatically formed.
Next, a case in which part of an AV stream is deleted will be described with reference to FIG. 2. As shown in a left portion of FIG. 2, Real PlayList 1 before partial deletion is configured by PlayItem 1 that is considered to assign entirety of Clip 1. When an intermediate portion of Real PlayList 1 is deleted as a result of partial deletion of the AV stream, then, as shown in a right portion of FIG. 2, Real PlayList 2 after partial deletion is configured by two PlayItems, i.e., PlayItem 2 and PlayItem 3, in which PlayItem 2 indicates a Clip before a deleted Clip on the time base, and PlayItem 3 indicates a Clip after the deleted Clip on the time base.
Data of a stream portion subjected to partial deletion is erased from the disk. The Clip after partial deletion is present on the disk as one file. When Real PlayList 2 after partial deletion is reproduced, Clip 3 is reproduced consecutively from Clip 2.
Even if a Virtual PlayList is changed or erased, no change occurs in a Clip.
As described above, in the conventional proposal, when part of an AV stream is erroneously erased, there is no means for restoring the erased portion.
Another problem is that, even when erasure of a plurality of portions in one AV stream is intended, much time and troublesome operations are required because confirmation of partial deletion of a Real PlayList and deletion of stream data of a clip referred to by the Real PlayList from the disk are repeated.